<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Title</title>
    <script src="js/jquery-3.2.1.min.js"></script>

    <script>
        $(function(){

            $.ajax({
                url:"UserServlet",
                type:"post",
                dataType:"json",
                success:function(data){
                    $.each(data,function(i,user){
                        alert(user.username)
                    });
                }
            });
        });

    </script>
</head>
<body>
<h2>Hello World!</h2>


<table width="400px" cellpadding="0">
    <tr>
        <td>编号</td>
        <td>姓名</td>
        <td>密码</td>
    </tr>


</table>


</body>
</html>